Engine and gear coupling



March 31,1942. H. LIEBERHERR 2,278,181

ENGINEIAND GEAR COUPLING 5 4 sheds-sheet 1 Filed May 15, 1940 INVENTORH0275 Ze fra/2* f' ATTORNEYS March 31, 1942. l H, .L lEBERHERR 2,278,181

ENGINE AND-GEAR COUPLING Filed May l5, 1940 4 Sheets-Sheet 2 I lNvENToR#ans zeerexr ATTORNEYS March 31, 1942. H. LIEBERHERR ENGINE AND GEARCOUPLING Filed May 15, i940 v 4 Sheets-Sheet 3 lNvENToR Il i mw S5 E N RO T T A March 31, 1.942; l LESER-HERR v 2,278,181'.

, ENGINE AND (WAR- COUPLING I INVEN-roR f/ams' zeererf Patented Mar. 31,1942 ENGINE AND GEAR COUPLING Hans Lieberherr, Winterthur, Switzerland,as-

signor to Sulzer Frres, Socit Anonyme,

Winterthur,l Switzerland Application May 15, 1940, Serial No. 335,249 InSwitzerland May 17, 1939 I Cl. 60-18) Claims.

This invention relates to apparatus for the coupling of a reciprocatingengine to a turbo machine. The invention aims to provide ,a gearcoupling for interconnecting the engine shaft and a turbo machine whichis arranged to equalize the forces or torques transmitted between theengine and the turbo machine. The turbo machine may be a blower, forexample a supercharging blower or a turbine. The coupling comprises aplurality of intermeshing toothed wheels (hereinafter called gears)provided with a suitable closure, for example a casing, and a fluidsystem so arranged and connected to the coupling that the coupling mayoperate as a pump or as a motor.

The uid system comprises an accumulator for the storage of'the fluidunder pressure, and suitv'air under pressure and serve partly as an airvessel, and at least one relief valve may be connected to it, by meansof which accumulating or compensating action can be variously adjusted.At least one gear mechanism may be provided for the forward running ofthe engine and at least one other gear mechanism for the reverse runningof the engine. In addition to that, a reversing member may be providedto which the air vessel of the accumulator is connected alternately,according to the direction of. rotation, to theI gear mechanism forforward running, or to the' gear mechanism for reverse running. To theair vessel of the accumulator a liquid pumping device or a device forsupplying gas may be connected.

The V pipe connections to the gear mechanism may be short circuited inorder to put the gear coupling out of operation. With the engine workingwith supercharging through a turbo blower, the quantity or the pressureof the liquid in the accumulator may be adjusted to different valves inorder tov vary the supercharging pres- Sure.

The accompanying drawings illustrate appara-I tus embodying theinvention, in which:

Fig. 1 is a side view of a non-reversible internal combustion engine,turbo machine and gear cou ymeshing with the central gear I2.

Fig. 4 illustrates more or less diagrammatically and with parts shown insection, a battery of accumulators, an enlarged cross-sectional viewalong the line IIA-4A (part A), a cross sectional view along the lineIIB- 4B (part B), and a cross sectional View along the line IIC-4C (partC) each of Fig. 6;

Fig. 5 is a fragmentary'view 0f the multi-way cocks of Fig. 4 indifferent positions; i

Fig. 6 is a side view with parts shown in section of a modified form ofgear' coupling;

Figs. 7 and 8 are more or less `diagrammatic illustrations of modifiedforms of accumulators; and

Figs. 9 and 10 are side views of modied forms of apparatus utilizing thegear coupling of the invention.

The apparatus illustrated in Fig; 1 comprisesl an internal combustionengine I, preferably of the non-reversible type, provided with asupercharging blower 2 driven partly by the crankshaft 3 and partly byan exhaust gas turbine 4. The blower 2 is preferably directly coupled tothe turbiney 4 and indirectly coupled to the crankshafts throughchangespeed gears 6, 1, 8 and 9 to the gear coupling I0. y

The gear coupling III comprises spur gears II These gears are enclosedby a casing formed of the casing member I3 and thecover III in such away that the gears may operate not only as a liquid pump, but also as aliquid motor as hereinafter described. The crankshaft 3 is rigidlyconnected to f the casing member I3 by an intermediate cou- Fig. 3 is asectional view along the line 3-3 of Fig. 2;

pling member I5. In case of necessity a part or the Whole of the poweroutput of the internal combustion engine may be transmitted to the sh itI6 yconnected to the casing member I3. The geary I2, hollow shaft I1 andgear 6 are integral; however, the gear I2 and gear 6 may be keyed to ahollow shaft such as shaft I1.

Thel ducts 20 Iand 2| (Fig. 3v) of the' casing member are each connectedto a liquid pressure accumulator and 26 respectively (Fig. 2). Theaccumulators 25 and 26 and the pipes connected thereto form anaccumulator system. It is understood that other suitable systems may bearranged in various ways without departing from the invention. The duct2l) is connected through the duct 21 (Fig. 2) .with 'the annular space28 of the bearing 29 and the duct :lis ,connected with the annular spaceT30 through the d'uct 3I. The' two annular spaces 28 and 30 areconnected by pipes and 36 with the liquid pressure accumulators 25 and26 respectively.

A liquid pressure medium, for example oil'under pressure, is supplied bymeans' of the pump 31 through the non-return valves 33v4 and 39 to thepipes 35 and 36 and to the pressure accumulators /25 and 26. The liquidpressure accumulators 25 and 26 are also connected through pipes 40 witha compressor 4I, by means of which a gaseous pressure medium, forexample compressed air, can be introduced into the accumulators (airvessel parts) to act as a pressure cushion. 'I'he pipes 40 may be closedby means of the valves 42 and 43 when a suiilcient pressure cushion isavailable in the accumulators.

The accumulators 25 and 26 have relief valves 44 and 45, and thepressure at which they blow off may be adjusted as desired by means ofthe screws 46 and 41 respectively. Since the relief valves are connectedto the .dip pipes 48 and 46, only the liquid at the bottom of theaccumulators, but not the gas located above the liquid as pipe 36 whichis connected to accumulator 26 through valve 39, and the liquid flowing.from the accumulator 26 passes through pipe 5| into pipe 35 which isconnected to accumulator 25 through valve 38.

When the machinery is set into motion, the engine crankshaft begins torotate in the direction ofthe arrow 55 (Fig. 2), while the blower, thechange-speed gear and also the gear I2 remain at rest in consequence oftheir inertia. The

gears I| turn on the gear I2, which is at rest,

in the direction of the arrows 56 (Fig. 3). Relatively to the casing,consequently, the gears |I rotate in the direction of the arrows 51. Inthis way gears II and I2 begin to act as a pump and liquid is deliveredfrom duct 2I| into duct 2|. From the accumulator 26 liquid ilows throughthe pipe 35 to the annular space 28 and duct 21. The displaced liquidflows through duct 3|, annular space 3|) and pipe 36 intovthe pressureaccumulator 25 and thereby compresses the air cushion above the liquid.Consequently the pressure in accumulator 25 rises in comparison with thepressure in accumulator 26.

In consequence of the transmission through the change-speed gear, thegas blower wheel rotates at a speed several times greater than that ofthe crankshaft, so that a considerable amount of kinetic energy must bestored in it before it can a cushion, can iiow out. The liquid flowingout of the accumulator 25 passes through pipe 50 into come up to servicespeed. The resistance at the gears II against the relative rotationcaused by the rolling, increases only when the pressure differencebetween the accumulators 26 and 25 increases. This relative rotationbecomes slower, and in proportion to the slowing down, the'gear I2begins to rotate in the direction of the arrow 58 (Fig. 3), until, inthe steady state, the pressure difference between the accumulators 26and 25 is large enough to prevent rotation of the gears relative tothecasing |3, so that the gear I2 turns at the same speed as the crankshaft3. The rotating masses of the blower and of the changespeeg gear arethen accelerated to their service spee If fluctuations occur in theengine torque during service, for example in consequence of a change inangular velocity at the crankshaft, in the known forms of construction,the forces in the transmitting elements become increased in consequenceof the considerable kinetic energy of the rotating masses of the gasblower.

When the speed of the engine accelerates in comparisonV with the speedof the gas blower, the gears I I and I2 continue to act as a pump.Consequently more liquid is delivered from the'duct 26 tothe duct 2| andthe pressure in accumulator 26 .therefore rises still further ascompared with the pressure in accumulator 25. The speed of the blowerincreases slowly in accordance with the energy stored in accordance withthe pressure difference between the accumulators 25 and 26. Any undueacceleration of the blower and impermissible forces due to the rotatingmasses and the transmission are prevented.

If the speed of rotation of the crankshaft is retarded in comparisonwith the speed of rotation of the blower shaft, the liquid in duct 2|andthe accumulator 26 will be reduced in pressure. The gears and I2 thenact as a liquid motor which is driven by the energy stored inaccumulator 26 and this consequently prevents the speed of rotation ofthe blower shaft from being too quickly retarded. Consequently therecannot be any dangerous forcescaused by inertia and transmission. I

The storing and discharging of energy in and from the accumulators 25and 26, and also the action of the gears as liquid pump and as liquidmotor, result in that, when the angular velocity of -v a crankshaft issubject to periodic fluctuations and when other rapid changes inrotation may occur, the transmitting devices, particularly the gears,are protected from becoming too highly stressed in consequence' ofinertia forces. In addition to that, the energy which is superfluous atthe time of the acceleration is not lost, but is stored and can beutilized during the retarding period.

By4 appropriate adjustment of the screws 46 and 41 on the relief valvesof the accumulators, a greater or less flexible action may be obtained.Should the resistanec of the blower become too great, for examplebecause of some damage, the liquid pumped between the gears and I2 willsimply flow over through the valve45 and the pipe 5I from accumulator 26into accumulator 25. The gears then act as 'a slip coupling, and thetransmission gear cannot be damaged.

In addition to that, it is possible through a multi-way cock 60 (Fig. 2)ltted in the pipes 35 and 36 to short-circuit the ,two ducts 20 and 2|so that the gears no longer transmit any power from the crankshaft tothe blower. is then at rest, unless it is driven by an exhaust gaslturbine, and the internal combustion engine works without supercharging.

The apparatus shown in Figs. 4 and 6 is for reversible machines, andcomprises an intermediate coupling member I5 connected to a ring gear 6Iwith internal teeth which mesh with the spur gears II. The gearsA IItransmit the power tothe central gear 2, which drives the wheels 6 and 1of the change-speed gear over hollow A shaft |1.y 'Ihe gears I2 and 6|form an epicyclic gear train. The teeth of the ring 6I and of the gears|I and I 2 are enclosed by a casing formed by the casing member I3 andcover I4. The gears II can thus work together with gears I2 and 6I as aliquid pump or as a liquid motor. The ducts 20 and 2| `are connectedthrough the pipes 35 and 36 with the accumuiators 25 and 26respectively, as shown in Fig. 4. Duets 26 and 2| are connected throughthe casing member I3 (Fig. 6) and the shaft I6 connected with it throughthe annular spaces 28 and 3Ilof the bearing 2.9 by means ofthe ducts 3|and 32 as shown in Fig. 4 to the right.

The casing member I3 and the shaft I6 are not directly connected to thecrankshaft; the

shaft ls can turn with respect to the crankshaft.

The blower v 29 a gear 62 is keyed on shaft I6, and this gear mesheswith a second gear 63. The two gears are surrounded by a stationarycasing 64 and connected with ducts 65 and 66 in such a way that thegears may act not only as liquid pump but also as liquid motor.

The ducts 65 and 66 are connected through pipes '61 and 68 to the pipes35 and 36 respectively. By means of the valve 10, it is possible either,as shown in Fig. 4, to -close the connections to pipes 35 and 36, and toshort-circuit pipes 61 and 68, or, as shown in Fig. 5, to connect pipes61 and 68 to pipes 35 and 36. The valves 6D and 'I0 areconnectedtogether by means of levers 1| and I2 and rod 13 so that, inthe forward turning of the engine, valve 60 is set to connect ducts 20and 2| and the pressure accumulators, and valve I is set toshort-circuit ducts 65 and 66; and in the reverse turning of the engine,the valve In is set to connect ducts 65 and 66 to the pressureaccumulators and valve 60 is set to short-circuit ducts 20 and 2|.

When the engine is running forward and the valves 60 and 10 are in thepositions shown in Fig. 4, the crankshaft turns inthe direction shown byarrow V. Because ofA the short-circuiting of the ducts 65 and 66, thetwo wheelsv 62 and 63 encounter no resistance, shaft I6 and the casingmember are consequently free to rotate. In consequence of the inertia ofthe blower wheel and of the change-speed gear, gear I2 remains at firstat rest, so that the gears II can turn on it. In this way there isrotation of the axes of gears II and -of casing member I3 in thedirection of the arrow I4 and a relative rotation of gears II withregard to the casing in the direction of arrow 15.

From the duct liquid is delivered to the duct 2|. The liquid deliveredflows 'through pipe 36 into pressure accumulator 26 and compresses thegas cushion. The pressure in accumulator 26 rises as compared With thepressure in accumulator 25, and this acts as a brake on the relativerotation of the gears II. According to the strength of the braking, thegear I2 is carried along in the direction of the arrow I6 until nally,in the steady state, gear I2 rotates with the same angular velocity asthe gear 6| and the crankshaft.

If thereare any fluctuations in the speed or in the torque, the gearscome into action, according to the change of the pressures on the gears,either Aas a pump, thereby increasing the pres,- sure difference betweenaccumulators 2 5 or 26, or as a motor, thereby utilizing the pressuredifference between accumulators and 26. By change in the pressurediiference, or by the ilexible transmission thereby obtained betweencrankshaft and compressor, any undue increase in the accelerating orretarding forces and stresses is prevented.

` .When the engine is running 'in reverse, the

crankshaft turns in the direction of arrow R. The valves 6U and III areset in the positions shown in Fig. 5 for reverse running. In consequenceof its inertia the gear I2 remains at first at rest.' 'Thereby gears IIturn in the direction,

36 to the liquid accumulator 26. Consequently the pressure in liquidaccumulator 26 becomes greater than the pressure in accumulator 25.

As the overpressure rises, the resistance against the rotating of gears62 and 63, of shaft I6 and of casing member I3 increases, until theycome to rest. The gears will consequently stop running around gear I2,so that gear I2 will rotate in the direction of arrow 'I6 through gear6I and over gears II. The gear I2 and also the blower are always drivenin the same direction as shown by the arrow 'I6 when the shaft I6 isrotating forward IV) as well as when it is ro'- tating backward (R).

When the speed or the torque fluctuates, a variable resistance acts onthe casing member I3 and consequently on the gears 62 and 63. The gearswill consequently act either as a liquid pump and increase the pressuredifference of accumulators 26 and 25, or they will act as a liquid motorand decrease this pressure difference. The coupling may also act as afree-wheel mechanism when, for instance, the speed of the reciprocatingengine is to be quickly reduced. In consequence of the stored kineticenergy, the turbo machine will then take a longer time to come to rest.In this way any impermissible accelerating or retarding of the blowershaft is prevented. so that no impermissible forces due to inertia andtorques can arise.

The liquid in the accumulators may be loaded, instead of through a gascushion, by means of a piston under the influence of a weight (Fig. 7).Pistons and 86 of the accumulators 8'! and 88 are connected through therods 89 and 93 to the weighted levers 9| andi-92. If the pressureincreases atone piston it is pressed downvinards,v

and then the force exerted onA4 4it by the weight is increased.

The liquid in the accumulators may be loaded as shown in Fig. 8 in whichthe pistons 93 and 94are loaded by the springs 95 and 96 in theaccumulators 91 and 96 respectively. The spring pressure exerted on thepistons increases with the displacement of the pistons, so that anaccumulating action is also thereby obtained.

In the case of internal combustion reciprocatf ing engines, theoverpressure valves 44 and 45 may also be' utilized for varying thesupercharging pressure. If the tension of the valves is reduced untilslip occurs in the toothed wheel coupling, the supercharging pressurewill also be reduced in accordance with the reduced speed of the blower.

As shown in Fig. 9, the engine I has a shaft 3 connected throughcoupling I0 to a gas blower 4. As shown in Fig. 10, the engine I has ashaft 3 connected through the coupling I6 to a supercharging blower 2.

The invention may be adopted also, for instance, for additional drive ofthe crankshaft of a reciprocating engine by means of an exhaust turboblower as shown in Fig. 1.

I claim:

1. A gear coupling for interconnecting an internal combustion engine anda turbo machine which comprises a rotatable casing, spur gears rotatablein the casing, a central gear' meshing with the spur gears, means foroperatively interconnecting the engine and the turbo machine, a fluidsystem including means for supplying a liqu'd between the gears, anaccumulator for stor ing the liquid, separate pipes connecting the gearsto the accumulator for delivering liquid to the gears and for removingthe liquid from the gears, and means for loading the liquid in thecomprises a set of epicylic gears arranged for the transmission of powerin the forward running of the engine, another set of gears arranged forthe transmission of power in the reverse running of the engine, at leasttwo interconnected accumulators for the storage of liquid, meanscontrolling the pressure on the liquid, separate pipes connecting thegear train and the set of gears with each accumulator, and valve meansforshortcircuiting one set of gears or for permitting flow of liquidbetween an accumulator and a set of gears depending upon the directionof rotation of the engine.

5. A gear coupling according to claim 4 in which the epicyclic ,geartrain comprises a ring gear, a plurality of spur gears meshing with thering gear, a central gear meshing with the spur gears, and ducts forsupplying liquid between the spur gears and the ring gear and betweenthe central gear and thespur gears.

6. A gear coupling for interconnecting an internal combustion engine anda turbo machine which comprises a plurality of intermeshing gearsincluding a ring gear, at least one spur gear and a central gear, meansfor/coupling the ring gear to the engine and the central gear to theturbo Ina-,

chine, and a fluid system including at least one accumulator for storinga fluid under pressure, ducts connecting the gears to the accumulator,whereby thegears may act as a pump for forcing liquid into theaccumulator and also as a motor in being driven by fluid iiowing throughone of the ducts from the accumulator to the gears.

'7. A gear coupling for vequaliring the forces between a reciprocatingengine and a rotatable machine which comprises at least two gears inmesh with each other, a casing enclosing the gears and providing a spacewhere the gears mesh for a liquid, means for operatively interconnectingthe gear coupling to the engine and to the rotatable machine, anaccumulator system ar- A' cumulator system, a second set of gears whichis operable in the reverse running of the engine, valve means forconnecting or disconnecting the liquid accumulator systemI with each setof gears, whereby the mst-mentioned set of gears may be used in theforward running of the engine while the secqnd set of gears isinoperative and thesecond set of' gears may be used in the reverserunning of the engine while the first-mentioned set of gears isinoperative, and means interconnecting the engine, the coupling and therotatable machine. Y

9. A gear coupling for equalizing the forces between a reciprocatingengine and a rotatable machine which comprises a set of gears comprisingat least two gears in mesh with each other which is operable in theforward running of the engine, an enclosure for .the gears, an enclosedspace between the gears and the enclosure for a liquid, a liquidaccumulator system connected by pipe to the enclosed space, means forcausing the set of`-gears to operate not only as a liquid pump incharging liquid into the accumulator system, but

also as a liquid motor in receiving liquid in the of the engine whilethe first-mentioned Aset of gears is inoperative, and meansinterconnecting the engine, the coupling and the rotatable machine, saidtwo sets of gears being so arranged that the rotatable machine rotatesin the same direction in both the forward and the reverse* space betweenthe gears and the enclosure for a ranged to store liquid under pressureconnected engine, anA enclosure for the gears, an enclosed space betweenthe gears and the enclosure for a liquid, a liquid accumulator systemconnected by pipe to the enclosed space, means for causing the set ofgears to operate not only as a liquid pump in chargingliquid into theaccumulator system, but also as a liquid motor in receiving liquid inthe enclosed space underY pressurefrom the acliquid, duct meansconnecting the enclosed space .on one side of the gears with anaccumulator,

other duct means connecting the enclosed space on another sideV of thegears with another accumulator, said gears being arranged to act as apump in receiving liquid from one accumulator and forcing it into theother accumulator and gears with the other accumulator, said second setof gears being arranged to act as a pump in receiving liquid from oneaccumulator and forcing it into the other accumulator and to actas aimotor in receiving liquid from one accumulatorl and forcing it into'theother accumulator, and' means for selectively using one set of. gearsfor the forward running of the engine and the other set ofgears in thereverserunning of the engine. HANS .LIEBERHERR

